Aberrant right subclavian artery (ARSA) is considered a rare anatomical variant, with its reported prevalence in the general population ranging from 0.16% to 2%.
Understanding Aberrant Right Subclavian Artery (ARSA)
ARSA is an unusual anatomical variation of the right subclavian artery. Typically, the right subclavian artery originates from the brachiocephalic trunk. However, in cases of ARSA, this artery branches directly from the posterior aspect of the aorta, making it the last major vessel to emerge from the aortic arch. From this atypical origin, the ARSA commonly follows a course behind the esophagus to reach the right thoracic outlet.
Prevalence of ARSA
The reported commonness of ARSA varies across different studies, but it consistently falls within a relatively low range, affirming its classification as a rare variant.
| Prevalence Range | Description |
|---|---|
| 0.16% | Represents the lower end of the reported prevalence, indicating that approximately 1 to 2 out of every 1,000 individuals might have this anatomical variation. |
| 2% | Marks the upper end of the reported prevalence, suggesting it could be present in up to 20 out of every 1,000 individuals, making it a notable, albeit infrequent, finding. |
This variability underscores that while not extremely common, ARSA is a significant anatomical finding when identified.
Why Knowing About ARSA Is Important
Understanding the existence and typical course of an ARSA is crucial in various medical fields. Its retroesophageal path, for example, can be relevant in the diagnosis of certain swallowing difficulties or when planning surgical procedures in the neck and chest region, particularly those involving the esophagus or great vessels. Awareness of its prevalence helps medical professionals in considering this variant during diagnostic imaging or surgical interventions.
